This invention relates to the field of door manufacture and more particularly to the manufacturing of an insulated door having a glazing or window section installed therein, where the frame of said window section is installed during manufacture and is flush with both faces of the door.
The manufacture of decorative insulated doors for residential use is a process that marries a coloured and decorative skin or sheathing to both sides of a perimeter frame. The frame usually constructed from wood, has specially formed recesses into which the longitudinal edges of the decorative sheathing can be inserted after they have been in turn correspondingly bent to fit said recesses. Frictional engagement between the frame and sheathing components secure this assembly and lend rigidity to the door structure. This door and frame unit is typically insulated with an expanding insulating foam material which is applied through very small holes drilled through the wooden frame to provide access to the internal void.
As the insulating foam expands to fill the internal door cavity, it is likely to flow outwardly through any minute perimeter imperfections between sheathing and frame resulting in time consuming cleanup by production personnel.
As a result of the foregoing, frames for glazing or window units have not generally been installed at the time of manufacture. It is common that a portion of an insulated door is cut out after manufacture to accommodate pre-made glazing units available in a variety of shapes and sizes. Said units comprise a frame, having an outer portion which is slipped into the cut out portion from the outside and which bears against the outer face of the door. An inner portion is installed in opposed facing relation so as to bear against the inner face of the door. The inner and outer two portions are connected by screws passing from the inside portion to the outer. The two parts when assembled retain a separate thermally insulated glass window unit.
This process is typically not cost effective since the part cut out from the door, once removed, have no further use and are scrapped. The insulating value of the door is obviously compromised since any retro-fitted frame will be subject to thermal transmission. Further, the window frame must be located on the outside faces of the door surrounding the window opening which can be susceptible to moisture infiltration. The door face loses the smooth linear expression by being interrupted by a bulky frame. U.S. Pat. No. 4,897,975 discloses a door light which includes a frame incorporated structurally into the door and a glass removable from the frame. Glazing stops are provided to secure within the frame to allow for the insertion and removal of glass panels. While this patent does provide an integral door light frame, it may not adequately provide a weather-proof scal about the glass panel, nor does it provide an adequately insulated door where the insulation is continuous with the glass support portion of the door. There was therefore a need to develop a simple and efficient method for making an insulated door which is rigid and strong and can accommodate a suitable glass window that has a weather-proof seal. As will be evident, the present invention obviates the problems associated with the prior art methods.
In accordance with the present invention there is provided a method and apparatus for manufacturing a door, wherein the door has a rigid wooden frame having interior and exterior faces, metal sheathing secured to the rigid wooden frame by means of preformed grooves or recesses therein which securely accept suitably formed edge portions of the sheathing, a window frame, which may be of a suitable extruded plastic, the window frame for placing within a window opening defined by the wooden frame and sheathing, that is, formed by interior and exterior sheathing assembled onto the wooden frame, the window frame for accepting for mounting therein a thermally insulated window.
The window frame has integral, outwardly facing recesses to accept suitably formed edges of the interior and exterior sheathing, such as edges bent at right angles to the sheathing.
A resilient insulation seal is integrally formed at, or mounted to, the extremity of each of the outwardly facing recesses such as along the distal edge of the recess. The seal engages the inner faces of the door sheathing thereby preventing expanding foam insulation from escaping around the perimeter of the window frame. The insulation seals may be components which are separate from the window frame and are installed around the inner and outer perimeter of the window frame during assembly. An integrally formed shoulder is formed around an exterior perimeter, parallel to the length of each window frame member, to retain a double glazed window therein. The shoulder has a longitudinal internal void or thermal break. The interior perimeter of the window frame has formed therearound a slot or channel. A shoulder, notch or step is formed along at least one sidewall of the channel for mating engagement with a corresponding shoulder, notch or step in a mating resilient clip. The clip may be a channel member having opposed side walls, where a first side wall is mated into the slot or channel in the window frame to interlock the corresponding notches on the frame and clip. The second side wall is thereby pressed against the face of the double glazed window pane retained within the window frame.
Advantageously, the second side wall may be formed of a length to allow double glazed window units of different thickness to be accommodated within window frames having the same dimensions. In order that the clip functions as a spring clip to urge the second side wall against the window pane, the first side wall and the web extending between the first and second side walls may be formed at a slightly acute included angle therebetween.
According to an object of the present invention there is provided a flush glazed door comprising;
a rigid wooden frame having an opening for mounting an insulated window therein;
a metal sheathing secured on each side of said frame;
a window frame unit mounted within said wooden frame within said opening;
an insulated window positioned within said window frame unit; and
means for retaining said window within said frame in an air-tight and weatherproof manner.
The rigid wooden frame has a hollow internal cavity for the introduction of insulating foam therein such that when the window frame unit is mounted within said opening it is partially embedded within the introduced insulating foam as it cures.
According to another aspect of the present invention is a method for assembling a flush glazed door, said method comprising the steps of:
constructing a rigid wooden perimeter frame having an internal cavity therein;
fitting an exterior and interior metal sheathing to said frame;
securing a window frame within said perimeter frame;
filling said interior cavity with expanding foam insulation such that said window frame is partially embedded within said perimeter frame; and
mounting a window within said window frame.
The present invention provides a flush glazed door that is durable and thermally insulating and which allows one to manufacture the door without the glass insert therein such that no damage will occur to the glass as it can be easily installed at a job site. The door can accommodate varying sizes and thickness of glass and by virtue of the design of the window frame, a window can be installed therein and tightly secured in an airtight and weatherproof manner.